Service Engine Soon Light

JUANELL

MEMBER
1990 CADILLAC DEVILLE
V8
FWD
AUTOMATIC

The Service Engine Soon light has been coming on in my 1990 Cadillac Deville for about 6 mo. A mechanic checked the code and said it was EO39. I have driven it 2 mo. Since then. I notice no difference in how the car performs with the light on or off. It runs great, quiet, great pickup, etc. I asked a mechanic at a ransmission shop, and he told me he needed to overhaul my transmission for about $2,000. I said no and have been driving my car ever since. A few days ago the light came on and ididn't go off so I took the car and had the transmission flushed and serviced. The ligh went off, but today it came back on. What do you think about it? What do you think I should do? Thanks.

2 Replies

RASMATAZ

MECHANIC
75,992 POSTS

VCC ( viscous converter clutch )also known as the torque converter clutch-try using Lucas transmission additive treatment and see what happens-could also be the TCC Solenoid sticking

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Tuesday, November 30th, 2010 AT 6:41 AM

RASMATAZ

MECHANIC
75,992 POSTS

Might not be the same code-try pulling the codes

Ground terminals A and B with the ignition "ON" and engine not running. The system will enter the diagnostic mode. In this mode, the computer will display a 12, three consecutive times, by flashing the "CHECK ENGINE", "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR LAMP" or light. A 12 consists of one flash, a short pause, then two flashes in rapid succession.

After 12 is displayed, any stored trouble s will be displayed by flashing the "CHECK ENGINE", "SERVICE ENGINE SOON" or "MALFUNCTION INDICATOR LAMP" light. All s are displayed 3 times each then a 12 will repeat. In the diagnostic mode, the computer will also energize all computer controlled relays and solenoids.

E39 VCC Engagement Problem

Diagnostic Trouble Codes - 1990
Cadillac
E12 No Distributor Reference Signal
E13 Oxygen Sensor Not Ready
E14 Shorted Coolant Sensor
E15 Open Coolant Sensor
E16 Generator Voltage Out of Range
E19 Shorted Fuel Pump Circuit
E20 Open Fuel Pump Circuit
E21 Shorted Throttle Position Sensor
E22 Open Throttle Position Sensor
E23 EST Signal Problem
E24 Speed Sensor Circuit Problem
E26 Shorted Throttle Switch Signal
E27 Open Throttle Switch Signal
E28 Open Third or Fourth Gear Circuit
E30 ISC RPM Out Of Range
E31 Shorted MAP Sensor Signal
E32 Open MAP Sensor Signal
E34 MAP Sensor Signal Out Of Range
E37 Shorted MAT Sensor Signal
E38 Open MAT Sensor Signal
E39 VCC Engagement Problem
E40 Power Steering Pressure Switch Signal
E41 Cam Sensor Signal Problem
E44 Oxygen Sensor Signal Lean
E45 Oxygen Sensor Signal Rich
E47 BCM to PCM/ECM Data Problem
E48 EGR System Problem
E49 Air Management System Problem
E52 PCM/ECM Memory Reset
E53 Distributor Signal Interrupt
E55 TPS Misadjusted
E58 Pass Key Control Problem
E60 Cruise - Engaged Trans. Not In Drive
E61 Cruise - Vent Solenoid Problem
E62 Cruise - Vacuum Solenoid Problem
E63 Cruise - Set Speed vs Vehicle Speed
E64 Vehicle Acceleration
E65 Cruise - Servo Position Signal Problem
E66 Cruise - Engine RPM Too High
E67 Cruise - Switch Shorted
E68 Cruise - Command Problem
E74 Intermittent MAT Sensor Signal
E75 Intermittent VSS Signal
E85 Idle Throttle Angle Too High
E90 Cruise - VCC Brake Switch Signal Problem
E91 Cruise - PRNDL Switch Problem
E92 Heated Windshield Request Problem
E96 Torque Converter Overstress
E97 P/N to D/R at High Throttle Angle
E98 P/N to D/R In ISC Range
E99 Cruise - Servo Apply Problem

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